CD4+ T cells play a central role in orchestrating immune responses by assisting other cells of the adaptive or innate immune system. In early studies two classes of CD4+ T cells (Th1 and Th2) were identified. More recently, a new subset of CD4+ T cells, the Th17 lineage was identified. Th17 cells appear to have evolved as a branch of the adaptive immune system specialized in enhanced host protection against extracellular bacteria as well as some fungi and microbes not well covered by Th1 or Th2 immunity.
Th17 cells were identified in the context of the discovery of a new cytokine family, the IL-17 family, which is presently known to comprise six members (IL-17A-F). IL-17 (previously named CTLA-8) is mainly expressed by Th17 cells and was designated IL-17A to indicate that it is the founding member of this cytokine family. IL-17 members share no sequence homology with other presently known mammalian proteins and therefore constitute a distinct cytokine family. Structural features of IL-17 family members deduced from the crystal structure of IL-17F suggest that, similar to many cytokines, each of the family members is probably produced as a homodimer, although structural similarities imply that heterodimers may exist. Very recently, a heterodimer of IL-17A and IL-17F expressed by activated human CD4+ T cells was identified that signals through the IL-17RA/IL-17RC complex (Wright J. F. et al. (2008) J. of Immunol., 181, p. 2799-2805).
The identification of Th17 cells as central mediators in chronic inflammatory processes and as principal pathogenic effectors in several types of autoimmunity conditions previously thought to be Th1-mediated promises new therapeutic approaches (Weaver T. et al. (2008) Annu. Rev. Immunol., 25, p. 821-852). Indeed, the proinflammatory cytokine IL-17 is mainly expressed by Th17 cells and is present at elevated levels in synovial fluid of patients with rheumatoid arthritis (RA) and has been shown to be involved in early RA development. In addition, IL-17 is a potent inducer of TNF-alpha and IL-1, the latter being mainly responsible for bone erosion and the very painful consequences for affected patients (Lubberts E. (2008) Cytokine, 41, p. 84-91). Furthermore, inappropriate or excessive production of IL-17 is associated with the pathology of various other diseases and disorders, such as osteoarthritis, loosening of bone implants, acute transplant rejection (Antonysamy et al., (1999) J. Immunol, 162, p. 577-584; van Kooten et al. (1998) J. Am. Soc. Nephrol., 9, p. 1526-1534), septicemia, septic or endotoxic shock, allergies, asthma (Molet et al. (2001) J. Allergy Clin. Immunol., 108, p. 430-438), bone loss, psoriasis (Teunissen et al. (1998) J. Invest. Dermatol, 111, p. 645-649), ischemia, systemic sclerosis (Kurasawa et al. (2000) Arthritis Rheum., 43, p. 2455-2463), stroke, and other inflammatory disorders.
Consequently, anti-IL-17 compounds have potential as anti-inflammatory agents, a therapeutic approach in line with a number of in vivo studies demonstrating that IL-17 neutralization reduces inflammatory processes such as arthritis. For example, the early neutralization of endogenous IL-17 by an IL-17 receptor-IgG1-Fc fusion protein starting after the immunization protocol during the initial phase of arthritis suppresses the onset of experimental arthritis (Lubberts et al. (2001) J. Immunol., 167, p. 1004-1013). Moreover, treatment with a neutralizing anti-IL-17 antibody in an animal model after the onset of collagen-induced arthritis reduced joint inflammation, cartilage destruction and bone erosion (Lubberts et al. (2004) Arthritis and Rheumatism, 50; 650-659). Histological analysis confirmed the suppression of joint inflammation, and systemic IL-6 levels were significantly decreased after treatment with an anti-IL-17 antibody. In contrast, systemic as well as local IL-17 overexpression using an adenoviral vector expressing murine IL-17 accelerated the onset of collagen-induced arthritis (CIA) and aggravated synovial inflammation at the site (Lubberts et al. (2001) J. Immunol., 167, p. 1004-1013 and Lubberts et al. (2002), Inflamm. Res. 51, p102-104).
Even though antibodies are routinely employed for analytical, purification, diagnostic and therapeutic purposes due to their ease of production, high affinity and specificity to virtually any desired target antigen, these still have a number of serious drawbacks such as the necessity of complex mammalian cell production systems, a dependency on disulfide bond stability, the tendency of some antibody fragments to aggregate, limited solubility and last but not least, they may elicit undesired immune responses even when humanized. As a consequence, a recent focus for developing small globular proteins as scaffolds for the generation of novel classes of versatile binding proteins has emerged. For generating diversity and target specificity, typically surface components (e.g. extracellular loops) of a protein framework with suitable biophysical properties are combinatorially mutated for producing a protein library to be screened for the target binding specificities of interest (Binz, H. K., and Pluckthun, A. (2005) Curr. Opin. Biotechnol. 16, 459-469).
These non-immunoglobulin-derived binding reagents are collectively designated “scaffolds” (Skerra A. (2000) J. Mol. Recognit. 13, 167-187). More than 50 different protein scaffolds have been proposed over the past 10 to 15 years, the most advanced approaches in this field being (as summarized in Gebauer M and Skerra A. (2009) Curr Opinion in Chemical Biology 13:245-255): affibodies (based on the Z-domain of staphylococcal protein A), Kunitz type domains, adnectins (based on the 10th domain of human fibronectin), anticalins (derived from lipocalins), DARPins (derived from ankyrin repeat proteins), avimers (based on multimerized LDLR-A), affitins (based on Sac7d from the hyperthermophilic archaeon), and Fynomers, which are derived from the human Fyn SH3 domain.
In general, SH3 domains are present in a large variety of proteins participating in cellular signal transduction (Musacchio et al. (1994) Prog. Biophys. Mol. Biol. 61; 283-297). These domains do not occupy a fixed position within proteins and can be expressed and purified independently. More than 1000 occurrences of the domain are presently known with about 300 human SH3 domains (Musacchio A. (2003) Advances in Protein Chemistry. 61; 211-268). Although there is great sequence diversity among SH3 domains, they all share a conserved fold: a compact beta barrel formed by two anti-parallel beta-sheets (Musacchio A. (2003) Advances in Protein Chemistry. 61; 211-268). Typically, SH3 domains bind to proline-rich peptides containing a PXXP core-binding motif (Ren et al. (1993) Science 259; 1157-1161), but examples of unconventional SH3 binding sites have also been described (Karkkainen et al. (2006) EMBO Rep. 7; 186-191). Most of the SH3 domains sequenced so far have an overall length of approximately 60 to 65 amino acids, but some of them may feature as many as 85 amino acids due to inserts into the loops connecting the main conservative elements of the secondary structure (Koyama et al. (1993) Cell 72(6); 945-952). An alignment of different SH3 domains revealed conserved amino acid residues responsible for the proper structure formation as well as for the canonical proline-rich motif recognition (Larson et al. (2000) Protein Science 9; 2170-2180).
Recently the inventors demonstrated that the Fyn SH3 domain is a particularly attractive scaffold (“Fynomer”) for the generation of binding proteins because it (i) can be expressed in bacteria in soluble form in high amounts, (ii) is monomeric and does not aggregate when stored in solution, (iii) is very stable (Tm 70.5° C.), (iii) lacks cysteine residues, and (iv) is of human origin featuring an amino acid sequence completely conserved from mouse to man and, hence, non-immunogenic (Grabulovski et al. (2007) JBC, 282, p. 3196-3204).
The objective underlying the present invention is to provide new IL-17A binding molecules, in particular ones with high specificity and high affinity for IL-17A. It is a further objective to provide IL-17A-binding molecules, preferably IL-17 inhibitors, suitable for research, diagnostic and medical treatment, preferably for use in medicaments for treating and/or preventing IL-17A-mediated diseases and medical conditions.
Surprisingly, the above objectives were solved by polypeptides comprising an amino acid sequence selected from the group consisting of:    (i)(G/E)VTLFVALYDY-(X)a-D-(X)b-SFHKGEKF-(X)c-I-(X)d-G-(X)e-WW-(X)f-A-(X)g-SLTTG-(X)hGYIPSNYVAPVDSIQ  (I)            wherein a to h are 0 to 20,        preferably a is 1 to 10, more preferably 2 to 8, most preferably 6;        preferably b is 0 to 5, more preferably 1 to 3, most preferably 1;        preferably c is 0 to 5, more preferably 1 to 3, most preferably 1;        preferably d is 1 to 10, more preferably 3 to 9, most preferably 5 or 7;        preferably e is 0 to 5, more preferably 1 to 3, most preferably 1;        preferably f is 0 to 5, more preferably 1 to 3, most preferably 1;        preferably g is 0 to 5, more preferably 1 to 3, most preferably 1;        preferably h is 0 to 6, more preferably 1 to 3, most preferably 1 or 2;            (ii) an amino acid sequence having at least at least 70%, preferably at least 80%, more preferred at least 90%, most preferred at least 95% amino acid sequence identity to (i);    (iii) an amino acid sequence encoded by a nucleic acid that hybridizes to the complementary strand of a nucleic acid coding for (i), preferably under stringent conditions;    (iv) a fragment or functional derivative of (i) to (iii) derivable by substitution, addition and/or deletion of at least one amino acid,wherein said polypeptide binds to IL-17A.
The above generic formula (I) is the result of the repetitive and extensive mutational analysis of the human Fyn SH3 scaffold and selection based on IL-17A binding.
The positions designated X can be varied widely for the type of amino acid(s) and also the number of amino acids. Preferably, none of X are cysteine. The preferred number of amino acids for X is indicated by subscripts a to h, all of which are preferably 0 to 20, more preferably 0 or 1 to 10.
In native human Fyn SH3 (X)a and (X)d would correlate with the RT- and the Src loop, respectively. It is preferred but not necessary that (X)a and (X)d provide a loop structure. Typical loop structures are known to encompass 2 to more than 20 amino acids (Larson et al. (2000) Protein Science 9; 2170-2180). Hence, it is preferred that (X)a and/or (X)d have 2 to 20 amino acids. Preferably, a is 1 to 10, more preferably 2 to 8, most preferably 6. Preferably d is 1 to 10, more preferably 3 to 9, most preferably 5 or 7. Preferably (X)a is TAFWPG, more preferably VAFWPG, most preferably KAFWPG. Preferably (X)d is LNSSE, more preferably TRTSD or LHTSD, most preferably LRTSD.
(X)b, (X)c, (X)e, (X)f and (X)9 are independently of one another preferably 0 to 5, more preferably 1 to 3, most preferably 1. (X)h is preferably 0 to 6, more preferably 1 to 3, most preferably 1.
In a most preferred embodiment formula (I) is:(G/E)VTLFVALYDY-(X)6-D-(X)1-SFHKGEKF-(X)1-I-(X)5-7-G-(X)1-WW-(X)1-A-(X)1-SLTTG-(X)1-2GYIPSNYVAPVDSIQ  (Ia)
Of course, there are numerous variations in the amino acid sequence of formula (I) which will still allow for IL-17A binding of the polypeptides of the invention. Hence, the present invention also encompasses polypeptides comprising an amino acid sequence having at least 50, 60 or 70%, preferably at least 80%, more preferred at least 90%, most preferred at least 95% amino acid sequence identity to (i).
As used herein, the term “amino acid sequence identity” between amino acid sequences is meant to relate to the common and widely used alignment and comparison techniques of the person skilled in biochemistry. The amino acid sequence identity of two amino acid sequences can be determined by common alignment methods and tools. For example, for determining the extent of an amino acid sequence identity of an arbitrary polypeptide relative to the amino acid sequence of formula (I), the SIM Local similarity program can be employed (Xiaoquin Huang and Webb Miller, “A Time-Efficient, Linear-Space Local Similarity Algorithm.” Advances in Applied Mathematics, vol. 12: 337-357, 1991.), that is freely available from the authors and their institute (see also the world wide web: http://www.expasy.org/tools/sim-prot.html); for multiple alignment analysis ClustalW can be used (Thompson et al., “CLUSTAL W: improving the sensitivity of progressive multiple sequence alignment through sequence weighting, position-specific gap penalties and weight matrix choice.”, Nucleic Acids Res., 22(22): 4673-4680, 1994.). Preferably, the extent of the amino acid sequence identity of a polypeptide, a fragment or functional derivative of the invention to the amino acid sequence of formula (I) is determined relative to the complete sequence of formula (I).
Moreover, the present invention also encompasses polypeptides comprising an amino acid sequence encoded by a nucleic acid that hybridizes to the complementary strand of a nucleic acid coding for (i), preferably under stringent conditions. In other words, the amino acid sequence encompassed by polypeptides according to the invention is preferably defined indirectly by its coding nucleic acid that must still be capable of hybridizing to the complementary strand of a nucleic acid encoding the amino acid sequence of formula (I). Whether nucleic acids hybridize to one another is regularly determined in the art by specific alignment and comparison tools as well as experimentally. Next to common and/or standard protocols in the prior art for determining the ability of one nucleic acid to hybridize to a specifically referenced nucleic acid sequence under stringent conditions (e.g. Sambrook and Russell, Molecular cloning: A laboratory manual (3 volumes), 2001), it is preferred to analyze and determine the ability of an arbitrary nucleic acid encoding a polypeptide of interest to hybridize to the complementary strand of a nucleic acid sequence encoding the amino acid sequence of formula (I) under stringent conditions by comparing these two nucleotide sequences with alignment tools, such as e.g. the BLASTN (Altschul et al., J. Mol. Biol., 215, 403-410, 1990) and LALIGN alignment tools. Most preferably, the ability of a nucleic acid coding for a polypeptide of interest suspected of being a polypeptide of the invention to hybridize to the complementary strand of a nucleic acid coding for the amino acid sequence of formula (I) is confirmed in a Southern blot assay under the following conditions: 6× sodium chloride/sodium citrate (SSC) at 45° C. followed by a wash in 0.2×SSC, 0.1% SDS at 65° C.
Furthermore, the present invention encompasses polypeptides comprising a fragment, preferably a functional fragment, or functional derivative of any of the above-mentioned inventive amino acid sequences.
Hence, the term “polypeptide or amino acid sequence according to the present invention” also encompasses functional fragments and derivatives of the polypeptide or amino acid sequence of the invention having the property identified above, i.e. binding to IL-17A. A functional derivative of the polypeptide or amino acid sequence of the present invention is meant to encompass any amino acid sequence and/or chemical derivative (non-natural amino acid equivalents, glycosylation, chemical derivation) thereof, that has substantially sufficient accessible amino acid residues or non-natural equivalents to demonstrate binding to IL-17A. In the functional derivative of the polypeptide or amino acid sequence of the invention one or more amino acids may be deleted, modified, inserted and/or substituted. Furthermore, in the context of a “functional derivative”, an insertion refers to the insertion of one or more amino acids into the above-described non-derivatized binding proteins. It is preferred with increasing preference that a functional derivative does not comprise more than 5, 4, 3, 2, or nor more than 1 amino acid change(s) (i.e. deleted, modified, inserted and/or substituted amino acids). In another embodiment, it is preferred with increasing preference that not more than 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, or not more than 1% of all amino acids of the polypeptide or amino acid sequence are changed (i.e. are deleted, modified, inserted and/or substituted amino acids). A substitution in a derivative may be a conservative or a non-conservative substitution, but preferably is a conservative substitution. In some embodiments, a substitution also includes the exchange of a naturally occurring amino acid with a non-naturally occurring amino acid. A conservative substitution comprises the substitution of an amino acid with another amino acid having a chemical property similar to the amino acid that is substituted. Preferably, the conservative substitution is a substitution selected from the group consisting of: (i) a substitution of a basic amino acid with a different basic amino acid; (ii) a substitution of an acidic amino acid with a different acidic amino acid; (iii) a substitution of an aromatic amino acid with a different aromatic amino acid; (iv) a substitution of a non-polar, aliphatic amino acid with a different non-polar, aliphatic amino acid; and (v) a substitution of a polar, uncharged amino acid with a different polar, uncharged amino acid. A basic amino acid is selected from the group consisting of arginine, histidine, and lysine. An acidic amino acid is selected from aspartate or glutamate. An aromatic amino acid is selected from the group consisting of phenylalanine, tyrosine and tryptophane. A non-polar, aliphatic amino acid is selected from the group consisting of glycine, alanine, valine, leucine, methionine and isoleucine. A polar, uncharged amino acid is selected from the group consisting of serine, threonine, cysteine, proline, asparagine and glutamine. In contrast to a conservative amino acid substitution, a non-conservative amino acid substitution is the exchange of one amino acid with any amino acid that does not fall under the above-outlined conservative substitutions (i) through (v). If a functional derivative comprises a deletion, then in the derivative one or several amino acids that are present in the reference polypeptide have been removed. The deletion should, however, not be so extensive that the derivative comprises less than 3, preferably less than 4, more preferably less than 5 and most preferably less than 6 amino acids in total. As mentioned above, amino acids of the polypeptide or amino acid sequence of the invention may also be modified, e.g. chemically modified. For example, the side chain or a free amino or carboxy-terminus of an amino acid of the polypeptide may be modified by e.g. glycosylation, amidation, phosphorylation, ubiquitination, e.t.c. The chemical modification can also take place in vivo, e.g. in a host-cell, as is well known in the art. For examples, a suitable chemical modification motif, e.g. glycosylation sequence motif present in the amino acid sequence of the polypeptide will cause the polypeptide to be glycosylated. In all embodiments referring to a functional derivative of the invention, it has to be understood that the amino acid sequence having formula (I) as defined herein above is the starting molecule into which the functional derivative is introduced. In the case of a insertion and in two starting molecules having identical sequences with the exception to that in the first molecule Xa equals 4 and in the second molecule Xa equals 5, molecules of identical length and possibly identical amino acid sequence will result, if the insertion into e.g. the C-terminal end of Xa is two amino acids in the first molecule and is one amino acid in the second molecule.
The polypeptides of the present invention bind IL-17A, preferably human IL-17A. Preferably, they bind specifically to IL-17A, i.e. they do not bind to other cytokines or bind these to a much lesser extent, preferably by a factor of at least 2, 5, 10, 50, 100, 500 or 1000 times lower. An exemplary and preferred ELISA assay for determining the binding specificities of polypeptides of the present invention is provided in Examples 6 and 7.
In a preferred embodiment, the polypeptides of the present invention bind human and cynomolgus IL-17A specifically and with high binding affinity.
In further preferred embodiments the polypeptides of the invention have a specific (in vivo and/or in vitro) binding affinity to human IL-17A, preferably with a KD of 10−7 to 10−12 M, more preferably 10−8 to 10−12 M, most preferably lower than 10−12 M. For example and also preferred, the binding affinity of polypeptides of the present invention can be determined according to Example 2 below.
In a most preferred embodiment, the polypeptides of the present invention are selected from the group consisting of SEQ ID NOs: 1 to 119 or a functional derivative thereof as appended to the description.
In a preferred embodiment the polypeptides of the present invention do not only bind but actually inhibit IL-17A (function). This capacity is demonstrated in Examples 3 and 10, where the polypeptides' ability to inhibit the induction of IL-6 in human dermal fibroblasts in response to the addition of IL-17A was demonstrated.
Moreover, the polypeptides of the present invention have high stability in solution, e.g. they are stable at 4° C. for at least 6 months in simple phosphate-buffered saline (see Example 4).
However, stability is not limited to in vitro compositions but has already been proven in mice injected intravenously with a polypeptide of the present invention (see Examples 5 and 12).
In conclusion, the polypeptides of the present invention are well suited for research, diagnostic and medical applications.
Next to substituting IL-17A antibodies they also allow for designing new and less immunogenic fusion proteins for in vivo and in vitro pharmaceutical and diagnostic applications. Hence, in a second aspect, the invention relates to a fusion protein comprising a polypeptide of the invention fused to a pharmaceutically and/or diagnostically active component.
As mentioned, a fusion protein of the invention may comprise non-polypeptide components, e.g. non-peptidic linkers, non-peptidic ligands, e.g. for therapeutically or diagnostically relevant radionuclides.
Preferably, said active component is a cytokine selected from the group consisting of IL-2, IL-12, TNF-alpha, IFN alpha, IFN beta, IFN gamma, IL-10, IL-15, IL-24, GM-CSF, IL-3, IL-4, IL-5, IL-6, IL-7, IL-9, IL-11, IL-13, LIF, CD80, B70, TNF beta, LT-beta, CD-40 ligand, Fas-ligand, TGF-beta, IL-1 alpha and IL-1 beta.
In another preferred embodiment, said active component is a toxic compound, preferably a small organic compound or a polypeptide, more preferably a toxic compound selected from the group consisting of calicheamicin, maytansinoid, neocarzinostatin, esperamicin, dynemicin, kedarcidin, maduropeptin, doxorubicin, daunorubicin, auristatin, Ricin-A chain, modeccin, truncated Pseudomonas exotoxin A, diphtheria toxin and recombinant gelonin.
In another preferred embodiment, the fusion protein according to invention is one, wherein said active component is a chemokine, preferably selected from the group consisting of IL-8, GRO alpha, GRO beta, GRO gamma, ENA-78, LDGF-PBP, GCP-2, PF4, Mig, IP-10, SDF-1alpha/beta, BUNZO/STRC33, I-TAC, BLC/BCA-1, MIP-1alpha, MIP-1 beta, MDC, TECK, TARC, RANTES, HCC-1, HCC-4, DC-CK1, MIP-3 alpha, MIP-3 beta, MCP-1-5, Eotaxin, Eotaxin-2, 1-309, MPIF-1, 6Ckine, CTACK, MEC, Lymphotactin and Fractalkine.
In a further preferred embodiment the polypeptide or fusion protein according to the invention contains artificial amino acids.
In further preferred embodiments of the fusion protein of the present invention said active component is a fluorescent dye, preferably a component selected from the groups of Alexa Fluor or Cy dyes (Berlier et al., “Quantitative Comparison of Long-wavelength Alexa Fluor Dyes to Cy Dyes: Fluorescence of the Dyes and Their Bioconjugates”, J. Histochem. Cytochem. 51 (12): 1699-1712, 2003.); a photosensitizer, preferably phototoxic red fluorescent protein KillerRed (Bulina et al. (2006) Nat Biotechnol., 24, 95-99) or haematoporphyrin; a pro-coagulant factor, preferably tissue factor; an enzyme for pro-drug activation, preferably an enzyme selected from the group consisting of carboxy-peptidases, glucuronidases and glucosidases; a radionuclide either from the group of gamma-emitting isotopes, preferably 99mTC, 123I, 111In, or from the group of positron emitters, preferably 18F, 64Cu, 68Ga, 86Y, 124I, or from the group of beta-emitter, preferably 131I, 90Y, 177Lu, 67Cu, or from the group of alpha-emitter, preferably 213Bi, 211At.
In another preferred embodiment, the polypeptide of the present invention may be directly or via a chemical linker attached to one or more non-polypeptide components as defined herein above.
In a more preferred embodiment of the fusion protein of the present invention said active component is one or more functional Fc domains, preferably one or more human functional Fc domains (see for example SEQ ID NO: 117-119 and SEQ ID NO: 130), which allow(s) for extending the in vivo half-life of the IL-17A binding polypeptides of the invention and some of which direct a mammal's immune response to a site of specific target binding of the inventive polypeptide component of the fusion protein, e.g. in therapeutic, prophylactic and/or diagnostic applications. The polypeptides of the invention can be fused either to the N- or C-terminus of one or more functional Fc domains or to both the N- and the C-terminus of one or more Fc domains. It is preferred that the fusion proteins of the invention comprise multimers, preferably tetramers, trimers or most preferably dimers of the polypeptides of the invention fused to at least one side, preferably to the N-terminus of one or more, preferably one Fc domain. In this respect, it is noted that the Fynomer-Fynomer-Fc fusion protein designated (2C1)2-Fc demonstrates the advantage of multimeric polypeptide-Fc fusions, which have a higher affinity to IL-17A than the corresponding monomeric 2C1-Fc fusion protein, as demonstrated in FIGS. 3e and 3f and Table II of Example 2 below. Hence, a preferred embodiment of the invention is directed to multimeric polypeptide-Fc fusion proteins.
A “functional Fc domain” of an antibody is a term well known to the skilled artisan and defined on the basis of papain cleavage of antibodies. Depending on the amino acid sequence of the constant region of their heavy chains, immunoglobulins are divided in the classes: IgA, IgD, IgE, IgG and IgM, and several of these may be further divided into subclasses (isotypes), e.g. IgG1, IgG2, IgG3, and IgG4, IgA1, and IgA2. According to the heavy chain constant regions the different classes of immunoglobulins are called [alpha], [delta], [epsilon], [gamma], and [mu], respectively. The functional Fc domain of an antibody is directly involved in ADCC (antibody-dependent cell-mediated cytotoxicity) and CDC (complement-dependent cytotoxicity) based on complement activation, C1q binding and Fc receptor binding. The four human IgG isotypes bind different receptors, such as the neonatal Fc receptor, the activating Fc gamma receptors, FcγRI, FcγRIIa, and FcγRIIIa, the inhibitory receptor FcγRIIb, and C1q with different affinities, yielding very different activities. It is known that the affinities to activating and inhibiting receptors of an Fc domain of a human antibody can be engineered and modified (see Strohl W. (2009) Curr Opin Biotechnol, 20, p. 685-691). As mentioned above, the invention therefore comprises Fc fusion(s) which allow(s) for extending the in vivo half-life of the IL-17A binding polypeptides of the invention, and which contains a functional Fc domain from human origin, preferably a human functional Fc domain of an IgG1 antibody (see for example SEQ ID NOs: 117-119 and SEQ ID NO: 130).
In a more preferred embodiment of the fusion protein of the present invention the active component is one or more engineered human functional Fc domains of an IgG1 with activating or silenced effector functions, preferably one or more engineered human functional Fc domains of an IgG1 with silenced effector functions, and most preferably one or more engineered human functional Fc domains of an IgG1 with silenced effector functions with a mutation in L234 and L235 (see for example SEQ ID NOs: 131-135), numbering according to EU index of Kabat (see Johnson G. and Wu T. T. (2000) Nucleic Acids Res. 28, p. 214-218).
A further preferred embodiment relates to polypeptides or fusion proteins according to the invention as mentioned above, further comprising a component modulating serum half-life, preferably a component selected from the group consisting of polyethylene glycol (PEG), immunoglobulin and albumin-binding peptides.
Moreover, it is preferred that the fusion protein of the invention comprises any of the above inventive IL-17A binding polypeptides, preferably those selected from the group consisting of SEQ ID NOs: 117 to 119 and SEQ ID NOs: 130-135 or a functional derivative thereof.
It is noted that the polypeptide or fusion protein of the invention is preferably monomeric but also encompasses multimers, preferably tertramers, more preferably trimers, or most preferably dimers of the inventive polypeptides.
Polypeptides and fusion proteins of the invention may be prepared by any of the many conventional and well known techniques such as plain organic synthetic strategies, solid phase-assisted synthesis techniques or by commercially available automated synthesizers. On the other hand, they may also be prepared by conventional recombinant techniques alone or in combination with conventional synthetic techniques.
In this respect, further aspects of the present invention are directed to (i) a nucleic acid coding for a polypeptide or fusion protein of the invention, (ii) a vector comprising said nucleic acid, and (iii) a host cell comprising said polynucleotide and/or said vector.
Preferably, the invention is directed to an isolated and purified nucleic acid, comprising                (i) a nucleic acid encoding for a polypeptide of the invention, preferably encoding the amino acid sequence of formula (I), more preferably(G/E)VTLFVALYDY-(X)6-D-(X)-SFHKGEKF-(X)1-I-(X)5-7-G-(X)1-WW-(X)-A-(X)-SLTTG-X)1-2-GYIPSNYVAPVDSIQ;        (ii) a nucleic acid having a sequence with at least 60 or 70%, preferably at least 80%, more preferred at least 90%, most preferred at least 95% sequence identity to the nucleic acid sequence of (i);        (iii) a nucleic acid that hybridizes to the complementary strand of a nucleic acid of (i) or (ii);        (iv) a nucleic acid, wherein said nucleic acid is derivable by substitution, addition and/or deletion of one of the nucleic acids of (i), (ii) or (iii);        (v) a fragment of any one of the nucleic acids of (i) to (iv), that hybridizes to the complementary strand of a nucleic acid of (i) coding for a polypeptide according to the invention.        
More preferably the nucleic acid of the invention comprises a nucleic acid coding for a polypeptide or fusion protein as described above. In this regard, it is understood that any of the nucleic acids (i) to (v), above, preferably encodes a polypeptide that binds IL-17A and more preferably inhibits IL-17A function.
Nucleic acids of the invention can be DNA, RNA, PNA and any other analogues thereof. The vectors and host cells may be any conventional type that suits the purpose, e.g. production of polypeptides and/or fusion proteins of the invention, therapeutically useful vectors and host cells, e.g. for gene therapy. The skilled person will be able to select those nucleic acids, vectors and host cells from an abundant prior art and confirm their particular suitability for the desired purpose by routine methods and without undue burden.
Preferably the nucleic acid is operably linked to a promoter, preferably linked to a promoter selected from the group of prokaryotic promoters consisting of T5 promoter/lac operator element, T7 promotor/lac operator element, or from the group of eukaryotic promoters consisting of hEF1-HTLV, CMV enh/hFerL promoter.
It is also preferred that a recombinant vector of the invention is one comprising a nucleic acid of the invention and preferably being capable of producing a polypeptide or fusion protein of the invention. Preferably such a vector is selected from the group consisting of pQE vectors, pET vectors, pFUSE vectors, pUC vectors, YAC vectors, phagemid vectors, phage vectors, vectors used for gene therapy such as retroviruses, adenoviruses, adeno-associated viruses.
In addition, the present invention relates to host cells comprising a nucleic acid and/or a vector of the invention.
Furthermore, the present invention encompasses an antibody that specifically binds a polypeptide or fusion protein of the invention. If the antibody binds to the fusion protein, it specifically binds to the portion thereof consisting of the polypeptide of the invention or an fusion epitope, i.e. the binding site of an antibody partially consisting of the polypeptide of the invention and partially consisting of a pharmaceutically and/or diagnostically active component, which is preferably a polypeptide or peptide. The antibodies may be polyclonal or monoclonal antibodies. As used herein, the term “antibody” refers not only to whole antibody molecules, but also to antigen-binding fragments, e.g., Fab, F(ab′)2, Fv, and single chain Fv fragments. Also included are chimeric antibodies, preferably humanized antibodies. Such antibodies are useful as research tools for distinguishing between arbitrary proteins and polypeptides of the invention. A further aspect relates to a hybridoma cell line, expressing a monoclonal antibody according to the invention.
Because the polypeptides and fusion proteins of the present invention demonstrate IL-17A-binding and inhibitory properties as well as storage and in vivo stability, a further aspect of the present invention relates to a pharmaceutical composition comprising a polypeptide or fusion protein, a nucleic acid and/or a recombinant vector of the invention and optionally a pharmaceutically acceptable carrier. The term pharmaceutical composition is meant to also encompass diagnostic compositions for in vivo use.
Pharmaceutical compositions of the invention may be manufactured in any conventional manner. In effecting treatment of a subject suffering from the diseases indicated below, at least one compound of the present invention can be administered in any form or mode which makes the therapeutic polypeptide or therapeutic fragment thereof bioavailable in an effective amount, including oral or parenteral routes. For example, compositions of the present invention can be administered subcutaneously, intramuscularly, intravenously, by inhalation and the like. One skilled in the art in the field of preparing formulations can readily select the proper form and mode of administration depending upon the particular characteristics of the product selected, the disease or condition to be treated, the stage of the disease or condition and other relevant circumstances (see. e.g. Remington's Pharmaceutical Sciences, Mack Publishing Co. (1990)). A suitable carrier or excipient may be a liquid material which can serve as a vehicle or medium for the active ingredient. Suitable carriers or excipients are well known in the art and include, for example, stabilizers, antioxidants, pH-regulating substances, controlled-release excipients, etc. A composition according to the invention is preferably provided in lyophilized form. For immediate administration it is dissolved in a suitable aqueous carrier, for example sterile water for injection or sterile buffered physiological saline. If it is desirable to produce larger volumes for administration by infusion rather than as a bolus injection, it is advantageous to incorporate human serum albumin or the patient's own heparinised blood into the solvent at the time of final formulation. Alternatively, the formulation can be administered subcutaneously. The presence of an excess of a physiologically inert protein such as human serum albumin prevents loss of the pharmaceutically effective polypeptide by adsorption onto the walls of the container and tubing used for the infusion solution. If albumin is used, a suitable concentration is from 0.5 to 4.5% by weight of the saline solution.
The IL-17A-binding and inhibiting polypeptides of the invention are particularly useful for the treatment and/or prevention of IL-17A- and/or Th17-related diseases or medical conditions. Hence, a further aspect of the present invention is directed to the use of a polypeptide or fusion protein, a nucleic acid and/or a recombinant vector of the invention for medical use, i.e. for the preparation of a medicament, preferably for treating and/or preventing a disease or medical condition, preferably selected from the group consisting of IL-17A and/or Th17-related diseases or medical conditions.
In a preferred embodiment, the medical use of the invention relates to treating and/or preventing of diseases or medical conditions selected from inflammatory, autoimmune and/or bone loss-related diseases and conditions.
In a most preferred embodiment, said inflammatory, autoimmune and/or bone loss-related diseases and conditions are selected from arthritis, preferably rheumatoid arthritis, arthritis chronica progrediente, reactive arthritis, psoriatic arthritis, enterophathic arthritis and arthritis deformans, rheumatic diseases, spondyloarthropathies, ankylosing spondylitis, Reiter syndrome, hypersensitivity (including both airways hypersensitivity and dermal hypersensitivity), allergies, systemic lupus erythematosus, inflammatory muscle disorders, polychondritis, sclerodoma, Wegener granulomatosis, dermatomyositis, Steven-Johnson syndrome, chronic active hepatitis, myasthenia gravis, psoriasis, idiopathic sprue, autoimmune inflammatory bowel disease, ulcerative colitis, Crohn's disease, Irritable Bowel Syndrome, endocrine ophthalmopathy, Graves disease, sarcoidosis, ischemia, systemic sclerosis, multiple sclerosis, primary biliary cirrhosis, juvenile diabetes (diabetes mellitus type I), autoimmune haematological disorders, hemolytic anaemia, aplastic anaemia, pure red cell anaemia, idiopathic thrombocytopenia, uveitis (anterior and posterior), keratoconjunctivitis sicca, vernal keratoconjunctivitis, interstitial lung fibrosis, glomerulonephritis (with and without nephrotic syndrome), idiopathic nephrotic syndrome or minimal change nephropathy, tumors, inflammatory disease of skin inflammation, cornea inflammation, myositis, loosening of bone implants, acute transplant rejection, metabolic disorders, atherosclerosis, diabetes, and dislipidemia, bone loss, osteoarthritis, osteoporosis, periodontal disease of obstructive or inflammatory airways diseases, asthma, bronchitis, pneumoconiosis, pulmonary emphysema, acute and hyperacute inflammatory reactions, diseases involving IL-17A-mediated TNF-alpha, acute infections, septicemia, septic shock, endotoxic shock, adult respiratory distress syndrome, meningitis, pneumonia, severe burns, cachexia, wasting syndrome, stroke, herpetic stromal keratitis and dry eye disease. All of the above specified diseases and medical conditions have in common that their origin and/or symptom(s) are IL-17A- and/or Th-17-related.
The amount and mode of administration of the inventive compounds, i.e. polypeptides, fusion proteins, nucleic acids, vectors, and host cells for treating and/or preventing a disease or medical condition, preferably selected from the group consisting of IL-17A- and/or Th17-related diseases or medical conditions, more preferably those specifically listed above, will, of course, vary depending upon the particular polypeptide or fusion protein inhibitor of the invention, the individual patient group or patient, the presence of further medically active compounds and the nature and severity of the condition being treated. However, it is presently preferred that for prophylactic and/or therapeutic use dosages of about 0.01 mg to about 20 mg per kilogram body weight, preferably about 0.1 mg to about 5 mg per kilogram body weight should be administered. Preferably, the frequency of administration for prophylactic and/or therapeutic uses lies in the range of about twice per week up to about once every 3 months, preferably about once every 2 weeks up to about once every 10 weeks, more preferably once every 4 to 8 weeks. IL-17A-binding polypeptides and fusion proteins of the Invention are conveniently and preferably administered parenterally, intravenously, preferably into the antecubital or other peripheral vein, intramuscularly or subcutaneously. IL-17A-binding polypeptides can also be delivered topically as eye drops. A preferred prophylactic and/or therapeutic treatment of a patient involves the administration of polypeptides of the invention once per month to once every 2 to 3 months or less frequently.
In consequence, the present invention also relates to a method of treatment, wherein a pharmacologically effective amount of the above pharmaceutical composition is administered to a patient in need thereof, preferably a patient suffering from IL-17A- and/or Th17-related diseases or medical conditions, more preferably one of the above specified diseases or medical conditions. The term “treatment” as used herein relates to the prophylactic and/or therapeutic treatment of a disease or medical condition.
The IL-17A-binding polypeptides and fusion proteins of the invention may be administered as the sole active ingredient or in conjunction with, e.g. as an adjuvant to or in combination with, other drugs, e.g. immunosuppressive or immune modulating agents or other anti-inflammatory agents, e.g. for the treatment or prevention of diseases mentioned above. For example, the IL-17A-binding polypeptides and fusion proteins of the invention may be used in combination with immunosuppressive monoclonal antibodies, e.g. monoclonal antibodies with affinity to leukocyte receptors, e.g. MHC, CD2, CD3, CD4, CD7, CD8, CD25, CD28, CD40, CD45, CD58, CD80, CD86 or their ligands; other immunomodulatory compounds, e.g. a recombinant binding molecule having at least a portion of the extracellular domain of CTLA4 or a mutant thereof, e.g. an at least extracellular portion of CTLA4 or a mutant thereof joined to a non-CTLA4 protein sequence, e.g. CTLA4Ig (e.g. designated ATCC 68629) or a mutant thereof, e.g. LEA29Y; adhesion molecule inhibitors, e.g. LFA-I antagonists, ICAM-I or -3 antagonists, VCAM-4 antagonists or VLA-4 antagonists. In addition, the polypeptides and fusion proteins of the invention may be used in combination with DMARD, e.g. Gold salts, sulphasalazine, anti-malarias, methotrexate, D-penicillamine, azathioprine, mycophenolic acid, cyclosporine A, tacrolimus, sirolimus, minocycline, leflunomide, glucocorticoids; a calcineurin inhibitor, e.g. cyclosporin A or FK 506; a modulator of lymphocyte recirculation, e.g. FTY720 and FTY720 analogs; a mTOR inhibitor, e.g. rapamycin, 40-O-(2-hydroxyethyl)-rapamycin, CCl779, ABT578, AP23573 or TAFA-93; an ascomycin having immuno-suppressive properties, e.g. ABT-281, ASM981, etc.; corticosteroids; cyclophosphamide; azathioprene; methotrexate; leflunomide; mizoribine; mycophenolic acid; mycophenolate mofetil; 15-deoxyspergualine or an immuno-suppressive homologue, analogue or derivative thereof; or a chemotherapeutic agent, e.g. paclitaxel, gemcitabine, cisplatinum, doxorubicin or 5-fluorouracil; anti-TNF agents, e.g. monoclonal antibodies to TNF, e.g. infliximab, adalimumab, CDP870, or receptor constructs to TNF-RI or TNF-RII, e.g. Etanercept, PEG-TNF-RI; blockers of proinflammatory cytokines, IL-1 blockers, e.g. Anakinra or IL-1 trap, AAL160, ACZ 885, IL-6 blockers; inhibitors or activators of proteases, e.g. metalloproteases, anti-IL-15 antibodies, anti-IL-6 antibodies, anti-IL-23 antibodies, anti-IL-22 antibodies, anti-IL-21 antibodies, anti-IL-12 antibodies, anti-IFN-gamma antibodies, anti-IFN-alpha antibodies, anti-CD20 antibodies, NSAIDs, such as aspirin or an anti-infectious agent. Naturally, this list of agents for co-administration is not limiting nor complete.
The invention is further described by way of illustration in the following examples, none of which are to be interpreted as limiting the scope of the invention as outlined in the appended claims.